Dall Sheep, Grizzly Bear and Wolf Project

PhD Project by Catherine Lambert Koizumi, Derocher
Lab

Recent surveys of Dall sheep
(Ovis dalli dalli) in the Richardson Mountains
(NT/YK border) have indicated a population decline and low
recruitment rates. The fluctuations of this population may
be shaped by a combination of factors, but the impact of
predation has received limited attention so far. Grizzly
bears (Ursus arctos) and wolves (Canis
lupus) are common in the Richardson Mountains, however
their demographic parameters, habitat use, nutritional
ecology, and impact on this sheep population remain poorly
known. To understand the spatial and predator-prey
interactions between these three species, my objectives are
to (1) evaluate the impact of predation on Dall sheep and
assess the viability of this population; (2) describe prey
selection and nutritional ecology of grizzly bears and
wolves; (3) characterize spatial interactions and resource
selection of Dall sheep, grizzly bears and wolves; (4)
analyze Dall sheep behaviour and predator avoidance
strategies; and (5) document aboriginal Traditional
Knowledge to complement our knowledge of Dall sheep,
grizzly bear and wolf interactions. Methods to accomplish
this multidisciplinary project include GPS tracking; fatty
acid signatures and stable isotopes analyses; field
observations of sheep behavior and kill sites
investigations; habitat, snow, and climate monitoring;
interviews with Gwich’in elders and active land users; and
integrated research with collaborative agencies. This
project was started in 2006 and is expected to last until
2009.
Keywords: Predator-prey interactions, spatial
dynamics, resource selection, behaviour, predator avoidance
strategies, viability, traditional knowledge, thinhorn
sheep, Ovis dalli, Canis lupus, Ursus
arctos, Northwest Territories, Gwich’in Settlement
Area.